Quick question to the audience before bedtime

[erratio]

Having just seen Med Revue at UNSW, the following question came to mind: Is one of these somehow 'better'; being grudging in your praise so that when you do give it out there's a sense of it being earnt; or giving lots of praise in order to create a positive mood and try encourage better performance overall, but at the risk of being seen as insincere in one's praise?